You have to build them yourself! There are many articles on bits and pieces of how to do this. The best area to start might be the Lead Nurturing Guide and the Revenue Cycle Modeler diagram.
Then think about how your current lead lifecycle works and how you might modify it to make it better: more data, better SLAs, etc.
Then implement any changes.
You can make good use of Trigger campaigns as leads change hands or statuses.
Lifecycle campaigns can take the form of data cleanup, lead routing, and more.
Thanks for the insight. This should get me started. I appreciate it.